1. Field of the Invention
The present invention relates to an improved specimen drawing device structured to facilitate the rapid drawing of a blood specimen from a patient in a cost effective, highly sanitary, and safe manner.
2. Description of the Related Art
One of the most common medical procedures performed on a patient involves the drawing of a blood specimen. Generally, one or a plurality of test tubes of blood are drawn for the purpose of testing and experimentation. Due to the amount of blood needed and further due to the various and numerous testing which must be performed on the blood specimens, conventional, disposable syringes cannot be practically utilized. Further, because of the frequent rate at which blood samples are taken, it can become quite expensive if an entire, disposable syringe must be utilized for each tube of blood to be drawn.
For these reasons, the art has turned to partially disposable specimen drawing devices. These partially disposable devices will generally include a reusable housing into which a sample collection apparatus, such as a test tube, will be interchangeably inserted. Further, because of the costs involved and frequent use of the device, the needle/cannula portion will generally be the sole disposable part of the entire apparatus, thereby enabling reuse of the housing by replacement of a new needle/cannula.
In the art, the most common type of blood drawing devices includes a hollow tubular housing wherein a disposable needle assembly is secured. In use, a portion of the needle will extend into the interior of the housing and an exterior portion of the needle, will extend out from the housing. When ready to use, the interior portion of the needle will be connected with a test tube or like collecting device, and the exterior portion will be inserted into a patient for drawing of the blood specimen. Once the sample is drawn, however, potentially hazardous circumstances arise.
Specifically, once a hospital worker has finished taking a blood sample, he or she must dispose of the needle portion. Generally, this will require replacing a protective cap or sheath over the needle tip, unscrewing the needle, and properly disposing of the needle in an approved waste container. Alternatively, some hospital workers will merely unscrew the needle without recapping, or will insert the needle portion into a sharp box rather than the cap before unscrewing the housing and disposing of the needle assembly. Such procedures, however, have many hazards involved therewith. For example, a primary hazard to health care workers involves replacement of the protective sheath, which should be a preliminary step to the unscrewing of the needle assembly. Because of the often stressful or rushed circumstances involved, it is a common occurrence during replacement that an interior of the sheath will be missed by the needle and the health care worker will be pricked by the needle tip. Additionally, there is a problem with blood contaminating the reusable portions of the apparatus. Generally, most disposable needles will include a retractable rubber guard over a portion of the needle that extends into the housing. The retractable guard will retract when the needle assembly is coupled with the test tube, and when the test tube is pulled from the needle the retractable guard extends back over the needle into its protective covering orientation. However, as this closure is taking place, the guard acts as a wipe which wipes blood from the external perimeter surface of the needle portion being covered. Consequently, a quantity of blood can remain at a tip of the retractable guard which can contact and contaminate the housing when the needle is unscrewed. Further, the blood can also run down an exterior surface of the retractable guard resulting in contamination of the surrounding reusable housing.
Accordingly, there is a substantial need in the art for a specimen drawing device which provides maximum safety and easy disposal of blood contacting portions, and which will appropriately isolate the blood contacting portions from reusable parts of the device.
In the past, others have attempted to address the disposability of the needle assembly, through the use of hinged or spring biased pivots to assist with ejecting the needle after use. While these devices eliminate the need to specifically unscrew the needle from the housing, they can also be quite expensive due to the number of moving parts and intricate interconnections which can lead to expensive molding and labor intensive manufacturing. Further, such devices do not address the important problem of contamination of the reusable portions of the assembly when attempting to dispose of the needle alone.
Therefore, there is still a need for a product which maximizes the overall safety involved in disposal and reuse of a select portion of the assembly, while maintaining the ease of use and low expense necessary to provide an effective and readily usable specimen drawing assembly.